$ 100^{-\frac{1}{2}}$
Solution: $= \left(\dfrac{1}{100}\right)^{\frac{1}{2}}$ Figure out what goes in the blank: $\Big(? \Big)^{2}=\dfrac{1}{100}$ Figure out what goes in the blank: $\Big({\dfrac{1}{10}}\Big)^{2}=\dfrac{1}{100}$ So $100^{-\frac{1}{2}}=\left(\dfrac{1}{100}\right)^{\frac{1}{2}}=\dfrac{1}{10}$